Correlations Between Intestinal Microbial Community and Hematological Profile in Native Tibetans and Han Immigrants.

Yan Ma,Ri-Li Ge,Shuang Ma,Qin Ga

doi:10.3389/fmicb.2021.615416

Abstract

Hematological features are one of the best-known aspects of high-altitude adaptation in Tibetans. However, it is still unclear whether the intestinal microbiota is associated with the hematology profile. In this study, routine blood tests and 16S rRNA gene sequencing were used to investigate the differences in the intestinal microbiota and hematological parameters of native Tibetan herders and Han immigrants sampled at 3,900 m. The blood test results suggested that the platelet counts (PLTs) were significantly higher in native Tibetans than the Han immigrants. The feces of the native Tibetans had significantly greater microbial diversity (more different species: Simpson’s and Shannon’s indices) than that of the Han immigrants. The native Tibetans also had a different fecal microbial community structure than the Han immigrants. A Bray–Curtis distance-based redundancy analysis and envfit function test showed that body mass index (BMI) and PLT were significant explanatory variables that correlated with the fecal microbial community structure in native Tibetans. Spearman’s correlation analysis showed that Megamonas correlated positively with BMI, whereas Bifidobacterium correlated negatively with BMI. Alistipes and Parabacteroides correlated positively with the PLT. Succinivibrio correlated positively with SpO2. Intestinibacter correlated negatively with the red blood cell count, hemoglobin, and hematocrit (HCT). Romboutsia correlated negatively with HCT, whereas Phascolarctobacterium correlated positively with HCT. A functional analysis showed that the functional capacity of the gut microbial community in the native Tibetans was significantly related to carbohydrate metabolism. These findings suggest that the hematological profile is associated with the fecal microbial community, which may influence the high-altitude adaptation/acclimatization of Tibetans.

Highlights

The Tibetan Plateau is both the largest and highest plateau in the world, with a mean elevation of 4,500 m (Zhao et al, 2019), and is considered as the “roof of the world.” It has special environmental conditions, such as low atmospheric pressure, low temperature, low relative humidity, and high solar radiation (Zhao et al, 2018)
Our results show that age, body mass index (BMI), SpO2, red blood cell (RBC), Hb, HCT, and platelet counts (PLTs) correlated with the intestinal microbial community structure, and that BMI and PLT were significant explanatory variables
We found that the feces of native Tibetans contain significantly greater bacterial diversity than those of the Han immigrants, whereas there was no significant difference in the microbial community richness in the two groups

Summary

Introduction

The Tibetan Plateau is both the largest and highest plateau in the world, with a mean elevation of 4,500 m (Zhao et al, 2019), and is considered as the “roof of the world.” It has special environmental conditions, such as low atmospheric pressure, low temperature, low relative humidity, and high solar radiation (Zhao et al, 2018). Lowland individuals (Han) can acclimatize to altitude to mitigate the effects of high-altitude exposure, and during this acclimatization, most changes occur over a period of days up to a few weeks (Muza et al, 2010; West et al, 2012; Qian-Qian et al, 2013). This process does not restore the individual’s performance to that at sea level, nor to one that is completely the same as that of the native population (Yang et al, 2018). Most microbes reside in the gastrointestinal tract, have coevolved with their hosts, and have profound effects on human physiology and nutrition (Turnbaugh et al, 2006; Tremaroli and Bäckhed, 2012)

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Conclusion